填空题costly/expensive
填空题half∧of the — 加入that
填空题despite of — 删去of
单项选择题A.Drastic changes in the weather have been common since ancient times.B.The change in weather from very cold to very hot lasted over a century.C.The scientists have been studying ice to forecast the weather in the future.D.The past 10,000 years have seen minor changes in the weather.
填空题for — 删去for